Bryan's a cool guy, learnt a lot online from him. It's funny I was going write a post about the lager cerevisiae fermentis weirdness years ago, glad he could answer some of it. It's still weird calling w34/70 cerevisiae since they would have had to get it from weihenstephaner's hefebank which would call it pastorianus.
For what it's worth all mangrove jacks yeast are cerevisiae.
De Clerk separated the yeast strains from a bottle of McEwan's and chose one which had a good fermentation profile btw.